Paper pulp agitator



May 17, 1949- J. A. RosMAlT 4 PAPER PULP AGITTOR 2 Sheets-Sheet l Filed March 10, 19,45

May 17, 1949. J. 'A. RosMAlT l PPER PULP AGITATOR 2 Sheets-Sheet 2 Filed March 10, 1945 IN V EN TOR.

A TTO fwn/5.

Panarea May 17, 1949 John A.

Rosmait, Appleton, Wis., assignor Murray Manufactum s Co., Wausau,

to D. J. Wis., a

corporation of lWisconsin Application March 10,

1945, serial 1 Claim. (Cl. 92-31) The present invention relates generally to improvements in therelates more particularly to improvements in the construction and operation of equipment for storing and agitating brous pulp stock preparatory to converting the same into paper.

Te primary object of my vpresent invention is lto provide an improved fibrous pulp storage and agitating systemespecially adapted for use in the production of paper, and lwhich is simplein construction and highly eilicient in operation.

It is customary in the paper making industry, to store considerable quantities of fibrous pulp stock comprisingA an abundance of water having the tiny pulp bres 'suspended therein, in large vats or chests; and unless the minute bres are constantly and thoroughly agitated while the pulp is thus stored, they will either sink or float art of paper making, and

capable of being built ln diverse shapes and sizes, and wherein undesirable deposition and accumulation of bres is eliminated while most effective agitation is produced, by proper formation of the chest walls and surfaces which bound the storage space.

thereby destroying the uniformity of the entire mixture. While various types of fibrous pulp storage and agltating methods and apparatus have heretofore been proposed and used commercially, all of these prior systems have proven objectionable either because they did not operate to maintain proper uniformity in the pulp mixture, .or because they were relatively complicated and therefore dilcult to manipulate and to maintain clean and free from undesirable nbre accumulation, or because they necessarily had to function as batch systems and could not be maintained in continuous operation. In the more successful of these prior pulp agitators, the pump for maintaining desired circulation of the mixture,was disposed outside of the storage space and special now directing elements ywere obstructively mounted within-the circulating chamber, thus-complicating the agitating equipment and making it relatively costly to install and dimcult tomalntain in clean condition.

It is therefore a more specic object of my' invention to provide an improved paper pulp storing and agitation assemblage which obvlates all of the above-mentioned dliiiculties and objections, and which is simplified by virtue of the fact that the circulating pump is confined vdirectly wherein obstrucis also reduced to within the pulp storage space tive flow circulating structure an absolute minimum.

Another specic object' of provide a. -pulp confining and this invention is to agitating chest Still another specific object of the presentinventlon is to provide a pulp stock storage and agitating vat to which fresh stock may be constantly admitted and from which thoroughly agitated and uniformlytreated stock may likewise be withdrawn, in an eiilci-ent and convenient manner.

A further specific object of the -invention is to provide improved pulp mixture agitating equipment which may be readily installed at moderate cost, and which is opera consumption to produce pulp stock of `extreme uniformity and of proper consistency. l

An additional specific object of my invention is to i provide an improved custom built pulp stock treating system, which may be readily constructed to meet any requirements, and which will occupy minimum space considering the actual capacity thereof.

These and other specific objects and advantages vof my present invention will be apparent from the following detailed description.

A clear conception of several typical embodiments of the invention, and of the mode of operating paper pulp stock agitating systems'built in accordance with the improvement, may be had by referring tothe drawings accompanying and forming a part of this specification, wherein like reference characters designate the same or similar parts in the various views. Fig 1 is a vertical section taken transversely through a typical pulp storage and agitating chest embodying my present invention, and having a preferred type of fresh pulp stock inlet and a transverse horizontal cross-section of any desired formation;

Fig. 2 is an elevation looking toward the front wall of a rectangular storage and agitating chest of the type shown in Fig. 1, stock inlet of the same type but additionally illustrating a typical pulp stock discharge pump;

` lllg.v.3`is a horizontal section taken transversely through the upper end of a square storage and agitating chest built according to |the invention,

e with minimum power also havingv a fresh.

3 and showing in dot-and-dash lines a modied location of the fresh pulp stock inlet; e

Fig. 4 is also a horizontal section taken transversely through the upper end of a rectangular chest such `as shown in Figs. 1 and 2, and also illustrating the modified arrangement of the fresh Pulp inlet;

Fig. is another horizontal section takenV l transversely through the upper end of an oval vat discharge type capable of producing the required circulation. and may be driven at any desired -speed from the exterior of the chest 8 by means of power applied through a pulley I8 or the like.

Iilhe upright stock circulating pipe I4 and its delivery branches Il are vpreferably formed of circular transverse cross-section in order to facilitate construction thereof; and while the treated fibrous pulp stock may be either intermittently pulp stock may be delivered to the upper portion storage and agitating tanks, vats, or chests of.v

definite shapes and adapted primarily for use in handling paper stock pulp, it is not my desire or intent to thereby unnecessarily restrict the scope or the utility of the novel features for analogous purposes.

Referring to the drawings, my present improved paper pulp stock storing and agitating equipment, comprises in general a normally enclosed receptacle or chest 8 forming a pulp confining and circulating chamber 9 which is preferably disposed symmetrical with respect to a central vertical plane and is provided with a rear wedge I0 located centrally of this plane; a low head liquid circulating pump I I confined directly within the lowermost central front portion of the chamber 9 and having a flaring approximately horizontal inlet I2 directed toward the wedge Il), and an upwardly directed outlet right circulating pipe I4 disposed concentric with the central plane of the chest and having its lower end in open communication with the pump outlet I3, while its upper extremity is provided withlaterally directed pulp delivery branches I5 extending away from said central plane near the top of the chamber 9.

The chests 8 may be constructed of re-enforced concrete, masonry, or other suitable material, and of any desired height and transverse in Figs. 3 to 6 inclusive.

I3; and an upof the chamber 9 at various localities. As illustrated in Figs. 1 and 2, thev fresh pulp is admissible to the chamber 9 either intermittently or continuously, through a supply pipe 2I which communicates with the upper extremity of the circulating pipe I4 midway between the branches I5. As depicted in Figs. 3 to 6 inclusive, the fresh stock may be introduced into the agitating chamber in a modiiledmanner, through a supply pipe 22 disposed in axial alinement with and above the upper extremity of the wedge I0, and the stock lmet pipe 22 may communicate with the washer or heater 28 as shown in Fig. 4.

It has previously been indicated, that the horizontal cross-sectional area of the chest 9 may assume various forms, and while Fig. 1 is a typical vertical section through a chest embodying the invention, different typical cross-sections which may be applied to these chests are shown In the embodiment of Fig. 3, the horizontal cross-sectional area of the agitating chamber 9 of -the chest 9 is square, except for the smoothly rounded corner portions 25 thereof; while in Figs. 2 and 4, the transverse cross-sectional area o.' the stock confining chamber 9 of the chest 9 is rectangular with similarly rounded corner portions 25. In the embodiment of Fig. 5, the horizontal cross-sectional area of the storage chamber 9 of the chest 8" is oval cross-sectional area, in order to provide the de-t sired capacity, and the interiors of these chests 8 should be devoid of sharp bre collecting corners and should preferably be provided with a smooth and hard surface or lining such as glazed tile, wherever the surfaces are contacted by the fluent stock. While the central rear flow directing wedge I0 which is formed integral with the chest 8, may be of uniform or of any other desired horizontal cross-section throughout its length, this wedge is preferably of gradually increasing cross-sectional area approaching the bottom thereof, as shown in the drawings, in order to provide a stable base for the massive structure and to make the wedge self-supporting, and to also permit free and unobstructed circulation of the fluent pulp near the top of the chamber 9. The bottom I8 of each chest 8 is also preferably inclined downwardly' and forwardly away from the wedge III, s as to permit disposition of the pump II in the lowermost portion of the chamber 9, and a suitable drain II may be provided at this lowermost chest portion, see Fig. 1.

The pulp stock circulating pump II which is conned directly within the stock confining chamber 9 and is ilrmly bolted to the front wall of the chest, may be of any suitable axial inlet radial with smoothly rounded opposite side walls 26; Whereas in Fig. 6 the transverse cross-sectional area of the circulating chamber 9 of the chest 8 is round lor circular, and the circulating pipe branches I5' have been directed at an angle re1- ative to each other to conform with this rounding. However, in each of the several modications, the wedge I0, circulating pump II, and pipe I4 are disposed in a common central plane, and all corner portions of the chamber bounding walls and bottom are smoothly rounded so as to eliminate sharp corners and flow obstructing and local whirl producing niches. All other portions 'of the various modified assemblages, are the same as previously described, and the functioning of theseveral units is precisely the same.

In view of the similarity in operation of the it will suflice to describe the normal operation of but one of them. During such normal opera-4 tion, the stock circulating and agitating pump II will be operated with the aid of the pulley I9, and the chamber 9 should be maintained filled to approximately the level indicated in Fig. 1 by admitting fresh pulp through the inlet pipe 2I, 22, and by withdrawing properly treated pulp stock through the outlet 20 with the aid of the discharge pump I9. 'I'hissupply and discharge of material may be carried on either continuously or at suitable intervals, and while the pulp is confined within the chamber 9, it is constantly circulated by the pump I I disposed directly within this chamber, as clearly indicated by the arrows in the various views. stock drawn into the-pump inlet I2 is'delivered by the pump upwardly through ,the riser pipe I4 and after being segregated into two equal streams, it is delivered against the .The fluent pulp'.

from `thebranches i9` curved corner portions of the side v struction lof the equipment is further facilitatedy I 'l and while the .improved storagevand -agitati'ngv e device is especially applicable for the:treatn'ient j I I to the exact details of construction or to the precise mode of use and Y walls of the chestl 8. Thetwo branch streams arethereafter caused to ow rearwardly and' to circulate freely in the upper unobstructed portion of the chamber 9, and eventually engage the smoothly curved surfaces of the wedge I0, wherefupon they are directed forwardly and intermingle at the central lower being ultimately again returned tothe pump Il for further circulation. During this constant' circulation of the pulp stock,'the pulp fibres are continuously agitated and maintained in uniform.

suspension and distribution throughout the masses of liquid, so that the stock which is portion of the chamber 9,

finally delivered from the chest by the pump i9 is always assured of uniform consistency.

From the foregoing. detailed description it will be apparent that my present invention provides an improvedv pulp stock storage `and a'gitating unit which besides being extremely simple and compact in construction, is highly eihcient in `normal use'and is adapted to most effectively treat the confined pulp. The location of the circulating pump directly within the treating chamber 9 is of considerable importance since it not only simplifies the entire assemblage, but also provides for most eicient continued circulation of the fibrous material without permitting undesirable floating or settlingof the fibres. The provision of the central wedge 19 and the location of this Wedge in central alinement with the pump inlet, also enhances the agitating effect posite side surfaces and insures most emcient treatment of all portions of the liquid; and the tapered formation of this wedge I0 and the inclined disposition of the chamber bottom I9, causes the liquid in all portions of they chamber 9 to be constantly agitated and thoroughly mixes the small nbres with all portions of the confined liquid. The improved umts may be custom built to meet various requirements, with either square, rectangular, oval, or circular transverse cross-sections, and by gradually rounding ,all corner portions of the interior of the chamber 9, undesirable accumulation of bres is positively eliminated. The installations can be readily built at minimum cost,

and by admitting the fresh bre' stock through an inlet pipe 2l communicating with the upper extremity of the circulating pipe il midway between the branches I9. rapid treatment of the fresh material is assured and the newly admitted fibres are quickly and uniformly mixed with the liquid material previously admitted to the chest 8. By forming the circulating D il and the branches IB thereof of circular crols-sectiomecnart,y

of fibrous paper'stock vantageously applied for other purposes.'

llt should be understood that it issired to limit this invention operation, herein shown and described, for various modifications lwithin the scope of'the alipended claims may occur to persons skilled inthe I claim:

A paper pulp agitator, forming a centrally chamber bounded by a andl a rear surface having an upright chamber bounding wedge projecting centrally 'and for'- wardly therefrom toward toward the mid-portion of the front surface, said wedge having concavely curved chamber bounding surfaces merging along smoothly curved opwith said front surface and being of gradually increasing l Y transverse cross-section approaching the bottom of the chamber, and said inclined downwardly and forwardly away Vfrom the largestl lower wedge end and cooperating with the wedge bounding surfaces to provide a continuous smooth upwardly and rearwardly inclined liquid guiding surface extending from the lowest frontl portion of the chamber to the uppermost rear portion thereof, and a circulating pump located within said chamber near the lowest midportion of obstructed inlet inopen communication with the chamber center and directed centrallyaway from the lower wedge extremity and also having an outlet directed upwardly along and laterally toward the opposite side surfaces of said chamber atsaid uppermost chamber portion.

JOHN A. ROSMAIT.

v REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number I p Name Date 537,260 Zimmermann et al. Apr. 9, 1895 1,716,297 Bond June 4, 1929 1,737,701 Bond Dec. 3, 1929 1,737,703 Bond Dec. 3, 1929 1,895,266 Morterud Jan. 24, 1933 2,164,944 Rosmait July 4, 1939 2,356,555 lAeldert Aug. 2 2, 1944 OTHER REFERENCES LMurray Mfg; Co., Wausau, Wis.. publica` tion PSA-4451'. 1,

comprising. chest unobstructed pulp storageV dat front upright surface the chamber center and l wedge-shaped chamber bottom being v said front surface and having an un. 

